The invention pertains to rotating fluid nozzles, and more specifically to rotating fluid nozzles for delivery of highly pressurized fluid to strip or clean a desired surface. It is to be understood that the term "clean" as used herein means to remove attached debris such as dirt, grease, oxides, and calcifications, for example, from the surface being worked. It is also understood that the term "strip" as used herein means to remove the exterior layer of molecules comprising the work surface itself.
Numerous fluid nozzles for operating on a surface are disclosed in the prior art. U.S. Pat. No. 4,821,961 issued to Shook discloses a self-rotating nozzle having a hollow shaft adapted for connection to a source of pressurized fluid. A body has an axial bore upon a central axis secured over one end of the shaft and has a counterbore. The shank with an end position extends from the body into which the counterbore extends with the counterbore terminating in a pair of radial ports. A head bears against the body and is journaled upon the shank. A fastener upon the end portion retains the head against axial movement relative to the body. A pair of spaced jet flow orifices are mounted upon outer portions of the head extending generally parallel to the central axis, but on oppositely extending axes inclined at a small acute angle to axes parallel to the central axis to provide a balanced rotational reactive power torque to the head. A pair of fluid passages in the head communicates with the ports and with the orifices respectively. The orifices are adapted to provide high velocity streams of pressurized fluid to a surface to be cleaned.
U.S. Pat. No. 5,024,382 issued to Shook et al. discloses a self-rotating nozzle substantially similar to the nozzle of U.S. Pat. No. 4,821,961 just discussed, except that the self-rotating nozzle of U.S. Pat. No. 5,024,382 discloses a pair of spaced jet flow orifices that are mounted upon outer portions of the head extending generally parallel to the central axis, but on oppositely extending axes canted at a small acute angle to axes parallel to the central axis to provide a balanced rotational reactive power torque to the head.
U.S. Pat. No. 5,217,163 issued to Henshaw teaches a rotating head mounted on a nozzle which creates cavitation in a pressurized fluid such that a surface may be quickly and efficiently cleaned. The rotation of the nozzle ensures a relatively wide cleaning path. The cavitation allows cleaning using only the pressurized fluid jet without any abrasive. The cavitating jet nozzle includes a pin received at a central position which lowers the pressure of the pressurized fluid such that cavitation bubbles form in the fluid. The pin is self-centering within the nozzle since it is free floating relative to a securing member which retains the pin in the nozzle. In addition, the pin preferably has an end face upstream of an outlet portion of the nozzle.
U.S. Pat. No. 5,248,092 issued to Rankin discloses a pulsating nozzle which includes a rotating head driven by reaction forces of high pressure water passing through outlets disposed at an angle to a plane normal to the axis about which the head rotates, and through a plurality of spaced passages extending partially circumferentially with respect to the axis.
U.S. Pat. No. 5,248,095 issued to Rankin et al. teaches a rotating nozzle for a high pressure water blasting system comprising a rotating body mounted on a fixed shaft having a high pressure water passage therein and adapted to discharge a stream of high velocity water through the nozzle opening in the body. The high pressure water passage is inclined relative to the longitudinal axis of the rotating body to direct the discharge from the nozzle in a circular path when the body is rotated.
U.S. Pat. No. 3,576,222 issued to Acheson et al. discloses a drill bit for the drilling of wells or the like in the earth by pressurized hydraulic fluid. A plurality of nozzles 54 extend downwardly through the bottom member 50 and backsplash plate 52 of a drill bit 46. The outlets of nozzles 54 are substantially in the plane of the lower surface of the backsplash plate. It is essential to this invention that the plurality of nozzles 54 slope downwardly in a direction having a component in a direction opposite to the desired direction of rotation of the drill bit 46, and that either no nozzles slope downwardly in the direction of rotation of the drill bit or the number of nozzles sloping in the direction of rotation is small enough that the reactive forces from the nozzles is overcome by the reactive force from nozzles sloping opposite the direction of rotation. Actually, nozzles sloping downwardly in the direction of rotation are detrimental to this invention in that they reduce the torque available to rotate the drill bit, and it is preferred that all of the nozzles slope to encourage rotation in the same direction. The nozzles may be sloped outward outwardly or inwardly as well as downwardly and in a direction opposite to the direction of rotation, as illustrated by nozzle 54a in FIG. 2. To provide an effective reaction force tending to rotate the drill bit, the slope of most of the nozzles sloping in a direction opposite the direction of rotation of the drill bit should be substantial, for example, at an angle of at least twenty degrees with the vertical. The maximum slope is limited largely by the space available. It is important to note that in Acheson, while the nozzles are angled, they appear to all be angled the same amount from the central axis, or are arbitrarily angled, in order to cause nozzle head rotation. Additionally, and most importantly, the Acheson nozzles are configured to form a solid water stream that impinges against the entire work surface. The nozzles 54 are positioned to impinge against substantially the entire bottom of the borehole as the drill bit rotates. The desired object of impinging against the entire bottom of the borehole may, for example, be obtained by locating nozzles, such as nozzles 54b and 54c, on one radius and nozzles 54d, 54e and 54f on another radius at different distances from the center of rotation. The angles and directions in which the nozzles slope downwardly can be varied to accomplish the desired object of impinging against substantially the entire bottom of the borehole in each revolution of the drill bit. Some of the nozzles, for example nozzle 54f, can be vertical.
A need thus exists for a rotating nozzle for use in cleaning or stripping a surface which includes a plurality of sets of jets with each of the sets of jets being disposed at a different distance from the center of the nozzle such that the nozzle produces a plurality of substantially circular concentric jet stream patterns which result in entire areas of the surface between adjacent circular concentric jet stream patterns being cleaned or stripped by the high pressure fluid streams after they initially impinge on the surface in the concentric circular patterns and as they are angularly deflected therefrom.
A need further exists for the above type of rotating nozzle wherein the sets of jets are configured at acute angles from the center of the nozzle and these acute angles and the different distances of the sets of jets from the center of the nozzle are selected such that the separate high pressure fluid streams for each of the sets of jets first converge, then intersect and finally diverge prior to impinging upon a surface to be cleaned or stripped.
A need finally exists for the above type of rotating nozzle wherein the acute angle of each of the sets of jets is different than the acute angle of the other sets of jets, and the different distances of the sets of jets from the nozzle's center are inversely proportional to the size of the acute angles of the sets of jets such that the set of jets having the largest angle is the shortest distance from the center of the nozzle and the set of jets having the smallest angle is the greatest distance from the center of the nozzle.